Ratchrt-driven odometer mechanism



March 31, 1931.

R. O. HELGEBY RATCHET DRTVEN ODOMETER MECHANISM Filed Feb. 1, 1928 of wt Patented Mar. 31, 193?;

UNITED STATES PATENT OFF-ICE RALPH OLAF IFIQEYT, MICHIGAN, ASSIGNOR TO A C SPARK PLUG COM- PANY, GE FLINT, MICHIGAN, A COMPANY OF MICHIGAN namcnrrnnlvnn DDOMETER- MECHANISM My invention relates to odometer mecha nism of the type in which he figure wl'ieels are driven from a rtchet eel which is interniittently rotated by a pawl eccentrically journaled on a driven shaft.

The principai object is to provide a simple and inexpensive but positive means for holdthe ratchet wheel stationary While the pawl is being advanced to the ne xt tooth on the ratchet wheel. Ordinarily this is accomplished by means of a member wh ch is spring held against the ratchet wheel and which engages the teeth. tion, however, this is effected by means ora z-rtainped spring member which fits snugly 111 a groove in the ratchet wheel and holds tne latter by friction only. The advantages are that there is less wear on the ratchet and eliciting noise caused by the h member sliding over the teeth is elimin ted.

Uther objects and advantages wi a parent upon referring to the spe and accompanying drawing, in

l is a vertical section th 01118.. i showing my improved h for the ratchet wheel in con 2 is a front View of with the face plate moved to show my invent i.

2 3 is a perspective View r stamping which serves to hol Wheel stationary while the pi va ed to the next tooth.

ne numeral indicates a s casing within which is held tatahiy carried in this frame is en by the us i sion or 0t t a speed indicatn. slow the rotor is a worn s with worm teeth cu 2:. This shaft is rota '2 r d the frame 12.

L 2 r .l: avnccl 26 by a spring 28, the in ens or which is secured about a rivet 3t ened to In my constructhe frame 12. The ratchet wheel is rotatably mounted on a shaft 82 which is supported in the frame 12. The odometer figure wheels 34, 36, 38, 40 and 42 are also rotatably mounted on the shaft 32. The ratchet wheel is provided with a groove 44 located between the wheel proper and a flange 46. A double tooth 48 is formed on this flange and is adapted to engage a star Wheel 50 once for each revolution of the ratchet Wheel. This star wheel is rotatably carried on a star Wheel shaft 52 which is also supported in the frame 12. The star wheel 50 is in constant mesh with a gear 54 on the figure wheel 34 and consequently the latter is moved one tenth of a revolution for each revolution of the ratchet wheel 26. The other figure wheels are each driven from the preceding one in the usual manner by star wheels 56.

will be readily seen that as the shaft 22 is rotated, the pawl 24 will be caused to move back and forth, due to the fact that it is eccentrically carried on the shaft. When it is moved toward the left hand side of Fig. 1,

will engage a tooth of the ratchet wheel 26 will turn the latter a part of revolutionl When the pawl is moved in the oppoits direction, it is necessary to provide some means for holding the ratchet Wheel stationary until the pawl has on aged the next tooth. This is accomplished iv means of a stamped spring member 58 made from any suitable material, such as phosphor bronze. This, member is mounted at one end upon the star wheei shaft 52 and is yoke shaped at its opposite so that itmay fit into the groove 44 and straddle the central portion of the ratchet wheel where it surrounds the shaft This stamped member is formed with curved portions 60 which are of greater IOU engages the teeth to kee the wheel from turning when the pawl is eing moved to the next tooth. The disadvantages of this construction are that since the spring member is 5 constantly bearing against the teeth, the latter will be apt to become worn to such an extent that the device will not function, and also there is a noticeable clicking noise caused by the spring member sliding over the teeth. It will be obvious that these ob- V jections are not encountered when using my construction, since the holding member does not operate in connection with the teeth.

It is thought from the foregoing, taken in connection with the accompanying drawing, that the construction and operation of the device will be apparent to those skilled in the art, and that various changes in size, shape and proportions and details of construction may be made without departing from the spirit and scope of the appended claims.

I claim 2-- 1. In combination, a rotatable member having a groove formed therein and carrying ratchet teeth, a pawl adapted to engage said ratchet teeth for the purpose of intermittently rotating said member, and means held in said groove and adapted to frictionally engage the walls thereof for the purpose of preventing rotation of said member while f the pawl is being retracted.

2. In combination with a ratchet driven mechanism including a ratchet wheel having a groove formed therein, and a pawl adapted to intermittently rotate said ratchet wheel, a compressible member held in said groove and adapted to frictionally engage the walls thereof for the purpose of preventing rotation of said ratchet wheel while the pawl is being retracted.

3. In an odometer mechanism including a ratchet wheel having a groove formed therein, a pawl adapted to intermittently rotate said wheel, a figure wheel, a transfer 5 pinion locatedv between said ratchet wheel and said figure wheel and adapted to rotate said figure wheel a part of a revolution for each revolution of said ratchet wheel, and a shaft upon which said transfer pinion is 70 journaled, a compressible member supported on said shaft and extending into said groove, said memberheing adapted to trictionally engage the walls of the groove for the purpose of preventing rotation of said ratchet wheel while the pawl is being retracted.

In testimony whereof I afiix my signature.

RALPH O. HELGEBY. 

